Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B7/00—Halogens; Halogen acids
  • C01B7/01—Chlorine; Hydrogen chloride
  • C01B7/03—Preparation from chlorides
  • C01B7/04—Preparation of chlorine from hydrogen chloride
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
  • B01J27/06—Halogens; Compounds thereof
  • B01J27/08—Halides
  • B01J27/10—Chlorides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
  • B01J27/06—Halogens; Compounds thereof
  • B01J27/08—Halides
  • B01J27/122—Halides of copper
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/582—Recycling of unreacted starting or intermediate materials

Definitions

• the present invention relates to an improved method for producing Chlorine from hydrogen chloride.
• a disadvantage of this concept is that the catalyst system is heated between the two reaction stages and cooled and optionally transported from one reaction zone to the other must become.
• the catalysts used e.g. can only 1 t vanadium oxide melt Release 10 kg of oxygen - this means a considerable technical effort, which consumes a large part of the advantages of the Deacon process.
• the poor space-time yield has a large number of other disadvantages like large stand volumes of molten salts, large apparatus volumes with correspondingly high investment costs and cost-intensive maintenance.
• large melting volumes with respect to the Keeping the temperature, heating up and switching off the system thermally only very poorly controlled, due to the thermal inertia of the large reactors is reinforced.
• reaction lower temperature, e.g. below 400 ° C. At these temperatures but there is the possibility of solids separation from the copper salt melt.
• the molten salt is therefore on a particulate inert carrier, e.g. Silica or alumina, attached and the reaction in the fluidized bed carried out (see GB-PS 908 022).
• a new proposal recommends Chromium-containing catalysts on inert supports, also a Temperature below 400 ° C is selected (see EP-A 184 413).
• the process according to the invention can be any hydrogen chloride Origin, e.g. any gas mixtures containing hydrogen chloride. Gas mixtures containing hydrogen chloride such as these are preferred chlorination and phosgenation. Such containing hydrogen chloride Gas streams can be in gaseous form or as aqueous hydrochloric acid absorbed in water the method according to the invention can be fed.
• the hydrogen chloride Depending on their origin, the gas streams containing them can be organic Contain impurities, e.g. Carbon monoxide, carbon oxide sulfide, phosgene and chlorinated and non-chlorinated organics, such as various chlorobenzenes.
• the content of organic impurities in the Keep hydrogen chloride as small as possible to keep formation to minimize undesirable, often toxic chlorine organics. This can be seen in known way, e.g. by absorption with water and / or by Adsorption on an adsorbent, e.g. Activated carbon.
• the required oxygen can be used as such or in a mixture with preferably use inert gases. Gases with oxygen contents are preferred of over 90% by volume.
• Salt melts without promoters can e.g. Mixtures of metal salts and salts lowering the melting point.
• Metal salts can be used for oxidation of hydrogen chloride with oxygen both catalytically active and catalytically be inactive salts.
• metal salts e.g. Salts of metals from the 1st to 5th main group and the I. to VIII. Subgroup of the Periodic Table of the Elements are used. Salts of aluminum, lanthanum, titanium, zirconium, vanadium, niobium are preferred. Chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper and zinc. Salts of vanadium, chromium, manganese, iron, cobalt, Nickel, copper and zinc. Copper salts are very particularly preferred.
• Melting point lowering salts can e.g. Salts of metals from I. to III. Main and sub-group and the IV. To V. main group of the periodic table of the elements, for example salts of lithium, sodium, potassium, Rubidium, Cesium, Magnesium, Calcium, Strontium, Barium, Aluminum, Gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, zinc and Silver. Salts of lithium, sodium, potassium, aluminum and zinc are preferred. Salts of potassium are particularly preferred.
• Melted salts without promoters are, for example, mixtures of the following type: LiCl / KCl, ZnCl 2 / KCl, KCl / NaCl / LiCl, MgCl 2 / KCl, AlCl 3 / KCl, AlCl 3 / NaCl, V 2 O 5 / K 2 SO 4 / K 2 S 2 O 7 , CrCl 3 / NaCl / KCl, MnCl 2 / NaCl, MnCl 2 / KCl, MnCl 2 / KCl / NaCl, MnCl 2 / AlCl 3 , MnCl 2 / GaCl 3 , MnCl 2 / SnCl 2 , MnCl 2 / PbCl 2 , MnCl 2 / ZnCl 2 , FeCl 3 / LiCl, FeCl 3 / NaCl, FeCl 3 / KC
• Mixtures of the type V 2 O 5 / K 2 SO 4 / K 2 S 2 O 7 , CrCl 3 / NaCl / KCl, MnCl 2 / KCl, FeCl 3 / KCl and CuCl / KCl are preferred. Mixtures of the type V 2 O 5 / K 2 SO 4 / K 2 S 2 O 7 , FeCl 3 / KCl and CuCl / KCl are particularly preferred. A mixture of KCl and CuCl is very particularly preferred.
• metal oxides for example V 2 O 5 , are used, these are converted into salts when the process according to the invention is carried out.
• the promoters to be added to the molten salts can e.g. Metal salts of subgroups I to VIII of the Periodic Table of the Elements and / or rare earths, such as salts of scandium, yttrium, lanthanum, Titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, Manganese, rhenium, iron, ruthenium, cobalt, rhodium, iridium, nickel, Palladium, platinum, copper, silver, gold and rare earth salts, such as salts for example cerium, praseodymium, neodymium, samarium, europium, gadolinium, as well as thorium and uranium.
• Metal salts of subgroups I to VIII of the Periodic Table of the Elements and / or rare earths such as salts of scandium, yttrium, lanthan
• Mixtures containing promoters are, for example, mixtures of the following type: LiCl / KCl / FeCl 3 , LiCl / KCl / NdCl 3 / PrCl 3 , KCl / NaCl / LiCl / FeCl 3 , KCl / NaCl / LiCl / NdCl 3 / PrCl 3 , MgCl 2 / KCl / FeCl 3 , MgCl 2 / KCl / NdCl 3 / PrCl 3 , MgCl 2 / KCl / LaCl 3 , MgCl 2 / KCl / CeCl 3 , AlCl 3 / KCl / FeCl 3 , AlCl 3 / KCl / NdCl 3 , AlCl 3 / KCl / PrCl 3 , AlCl 3 / KCl / NdCl 3
• V 2 O 5 / K 2 SO 4 / K 2 S 2 O 7 / FeCl 3 , FeCl 3 / KCl / NdCl 3 / PrCl 3 , CuCl / KCl / FeCl 3 , CuCl / AlCl 3 / FeCl are preferred 3 , CuCl / BiCl 3 / FeCl 3 , CuCl / CsCl / FeCl 3 , CuCl / FeCl 3 , CuCl / SnCl 2 / FeCl 3 , CuCl / ZnCl 2 / FeCl 3 , CuCl / KCl / NdCl 3 , CuCl / KCl / PrCl 3 , CuCl / KCl / LaCl 3 , CuCl / KCl / CeCl 3 , CuCl / KCl / NdCl 3 / PrCl 3 ,
• CuCl / KCl / FeCl 3 , CuCl / KCl / NdCl 3 , CuCl / KCl / PrCl 3 and CuCl / KCl / NdCl 3 / PrCl 3 mixtures are particularly preferred.
• a mixture of CuCl, KCl and FeCl 3 is very particularly preferred.
• the molten salts to be used can optionally also have several components from the group of the metal salts, the salts lowering the melting point and / or the promoters at the same time.
• molten salts which have at least 3 contain various components, at least one component being used for Metal salts, at least one component for salts lowering the melting point and at least one component meets the definition given for promoters.
• metal component of the described molten salt components several Can assume oxidation levels, for example iron, copper or vanadium, so can this metal component in any oxidation state or in any Mixtures of different oxidation levels are used.
• oxidation stage can be carried out in the process according to the invention to change.
• the proportion of the melting point depressants used in the process according to the invention Salts, based on the total melt, can be between 0 and 99% by weight, preferably between 10 and 90% by weight, and corresponds entirely particularly preferably about the composition of the eutectic mixture components used.
• the concentration of promoters in the molten salt can e.g. 0.1 to 100 Mol%, preferably 0.1 to 50 mol% and particularly preferably 0.1 to 10 mol% amount, each based on the entire molten salt.
• metal salts to be used in the process according to the invention melting point lowering salts and optionally promoters e.g. directly as Salts, e.g. use as halides, nitrates, sulfates or pyrosulfates.
• precursors of metal salts e.g. Metal oxides or hydroxides or elemental metals that occur in the implementation of the method according to the invention convert into metal salts. Chlorides are preferably used.
• the ratio of hydrogen chloride to oxygen can vary within wide limits become.
• the molar ratio of hydrogen chloride to Oxygen vary between 40: 1 and 1: 2.5. This ratio is preferably between 20: 1 and 1: 1.25, particularly preferably between 8: 1 and 1: 0.5 entirely particularly preferably between 5: 1 and 1: 0.3.
• the gas containing hydrogen chloride and oxygen is called continuous Phase led into a reaction zone and the molten salt dispersed therein.
• the continuous phase and the molten salt are preferably conducted in the Countercurrent to each other, realizes contact times between 0.1 and 4 seconds works at 350 to 550 ° C.
• Suitable reactors for this are e.g. Packing and Nozzle reactors, trickle film columns and spray towers.
• the gases coming from the reaction can, for example, 40 to 50 wt .-% Chlorine, 30 to 40% by weight hydrogen chloride, 0.5 to 10% by weight oxygen, 10 to 20% by weight of water (steam) and possibly inert gases, e.g. Contain nitrogen and possibly small amounts of organics.
• the possibly of entrained and / or volatilized salt melt components liberated reaction gases are preferably cooled rapidly to one Temperature below 300 ° C, preferably below 200 ° C and in particular to 120 to From 180 ° C.
• this cooling can be done in an injection cooler make.
• the reaction gases can be mixed in one already condensed, aqueous hydrochloric acid-filled absorption tower, if appropriate with the addition of fresh water, cool and hydrogen chloride and water condense together.
• the concentration of the aqueous hydrochloric acid obtained can be within wide limits can be varied, which is no problem for the person skilled in the art.
• the aim is to obtain 35 to 37% by weight aqueous hydrochloric acid (so-called concentrated hydrochloric acid).
• concentrated hydrochloric acid This can then be used for any purpose for which concentrated aqueous hydrochloric acid is known to be used.
• a cleaning known per se can be carried out, for example by blowing out with inert gas (e.g. air) and / or by absorption of impurities (e.g. on activated carbon). In this way e.g. the rest Chlorine and / or existing organics are removed. That way it is possible e.g. 5 to 15% by weight of the process fed to the invention Hydrogen chloride as a pure, preferably concentrated aqueous hydrochloric acid to obtain.
• inert gas e.g. air
• impurities e.g. on activated carbon
• the separated aqueous hydrochloric acid can also be used in other ways.
• the primary separated aqueous hydrochloric acid can be concentrated Add sulfuric acid and free it from the water.
• the so obtained preferably unpurified hydrogen chloride gas can then enter the reaction zone of the method according to the invention.
• the water of reaction in this case is obtained as more or less dilute sulfuric acid. This can used or concentrated in a known manner and so the water of reaction as such will be obtained.
• the one remaining after the cooling and separation of hydrogen chloride and water Gas stream essentially contains what is formed in the reaction zone Chlorine, unreacted oxygen, remaining portions of hydrogen chloride and Water vapor and possibly inert gases and / or possibly low Amounts of organics.
• the gas stream largely freed from the remaining water vapor contains for example 60 to 97 wt .-% chlorine and is now compressed to 2 to 10 bar.
• This compression can be carried out in one or more stages. It is preferable to work in two stages.
• compression devices come e.g. Piston compressors, rotary compressors and screw compressors in Question.
• the gas mixture is cooled to such an extent that the Chlorine liquefies. Suitable temperatures are e.g. at a pressure of 10 bar those below 34 ° C and at a pressure of 2 bar those below -20 ° C. At Suitable pressures can be extrapolated from other pressures determine these values.
• chlorine in liquid form which if necessary after further cleaning, in liquid form or after evaporation such as chlorine derived from the electrolysis of sodium chloride can. It is preferably used for chlorination and phosgenation organic compounds. If the separated chlorine in gaseous form the chlorine separated in liquid form can also be used Make stored cold usable for any cooling purposes.
• the gas remaining after the chlorine separation generally contains essential oxygen, minor traces of chlorine and hydrogen chloride, optionally inert gases and / or possibly small amounts of organics, mostly Chlorine organics.
• This gas is wholly or partly in the reaction zone of the recycled method according to the invention. It is advantageous, especially for prolonged implementation of the method according to the invention, only part of this Gases back and discharge the rest. You avoid one Accumulation of inert gas and organics in the reaction system.
• Out of the Part of the gas can contain environmentally harmful components, e.g. Chlorine, Hydrogen chloride and optionally organic impurities, in particular chlorinated organic contaminants by absorption and / or adsorption separate.
• the absorption can e.g. with water or aqueous alkalis
• the Adsorption e.g. performed with silica gel, aluminum oxides and / or activated carbon become. It is preferred to use regenerable activated carbon.
• the process according to the invention has a number of surprising advantages. So the reaction can be carried out in a reaction zone which is always uniformly active carry out the reaction is a constantly renewing surface of the Melting salt is available, you have extensive freedom regarding the choice of conditions for the melt and gas flows, it high sales and high space / time yields can be achieved only relatively small amounts of molten salt and relatively small apparatus required. It is also advantageous that the implementation without energy from outside, under continuous reaction management, without problems regarding long-term stability the reactors, with separation of the water of reaction in the form of a concentrated aqueous hydrochloric acid, with a high concentration of chlorine in the reaction gas and with a separation of the chlorine by compression and liquefaction without Foreign solvents can be carried out.
• An hourly gas mixture was in an apparatus to be operated continuously consisting of 3900 g hydrogen chloride, 854 g oxygen, 211 g chlorine and 192 g of nitrogen in a trickle film reactor at 370 ° C in the presence of a molten salt implemented.
• the molten salt consisted of 9000 g of the eutectic mixture from potassium chloride and copper (I) dichloride.
• To implement the Salt melt pneumatically at intervals with the feed gas stream in an above the storage container located promoted and continuously on the Filled packing filled. The diameter of the packed bed was 40 mm.
• the educt gas mixture preheated to 370 ° C. was from bottom to top passed through the packed bed.
• the hot product gas mixture leaving the reactor consisted of 780 g hydrogen chloride, 160 g oxygen, 3245 g Chlorine, 780 g water and 192 g nitrogen. It was in an injection cooler with 408 g of 34% by weight aqueous hydrochloric acid cooled to 150 ° C. and in a downstream, absorption tower already filled with 3526 g of 34% by weight aqueous hydrochloric acid the water of reaction formed and unreacted hydrogen chloride separated in the form of 34 wt .-% aqueous hydrochloric acid. In this way 397 g of hydrogen chloride, 769 g of water and 9 g of chlorine were separated off.
• reaction gas hourly 383 g hydrogen chloride, 160 g oxygen, 3236 g of chlorine and 192 g of nitrogen
• Sulfuric acid in one Drying tower dried, then compressed to 6 bar and to -10 ° C cooled down. This resulted in 2308 g of chlorine in liquid form, the additional 91 g Contained hydrogen chloride in dissolved form.
• the uncondensed portions of the Gases were led into a second condensation stage operated at -25 ° C, with another 576 g of chlorine and another 41 g of hydrogen chloride in liquid form were separated.
• a partial stream consisting of 100 g was made from the uncondensed residual gas Hydrogen chloride, 63 g of oxygen, 141 g of chlorine and 75 g of nitrogen were removed.
• the remaining gas flow 150 g of hydrogen chloride, 94 g of oxygen per hour, 211 g of chlorine and 112 g of nitrogen) were returned to the reactor.
• Example 1 It became more aqueous in an injection cooler with 29% by weight Hydrochloric acid cooled to 150 ° C and in a downstream absorption tower the water of reaction formed and unreacted hydrogen chloride in the form separated from 29 wt .-% hydrochloric acid. The separated amounts were 334 g Hydrogen chloride and 830 g of water. Furthermore, as in Example 1 proceed as described. A total of 3284 g of liquid chlorine were obtained, the 31 g Contained hydrogen chloride and 8 g of oxygen. From the uncondensed gas a partial stream was discharged, the hourly from 1 g of hydrogen chloride, 64 g Oxygen, 87 g of chlorine and 72 g of nitrogen existed. The residual gas was in the Reactor returned.
• Example 2 In a continuously operated falling film reactor, one was opened per hour 480 ° C preheated gas mixture consisting of 326 g hydrogen chloride and 71 g Oxygen at 480 ° C in the presence of a molten salt as in Example 1 described implemented.
• the product gas mixture leaving the reactor consisted of 218 g of hydrogen chloride, 47.2 g of oxygen, 104 g of chlorine and 26.5 g of water vapor.
• the product gases in an injection cooler cooled to 150 ° C. with aqueous hydrochloric acid, the Water of reaction separated in an absorption tower as aqueous hydrochloric acid, the Product gases with conc. Dried sulfuric acid and chlorine by compression 6 bar and cooling to -10 ° C in liquid form.
• Example 2 In a continuously operated falling film reactor, one was opened per hour 480 ° C preheated gas mixture consisting of 81.5 g of hydrogen chloride and 17.8 g of oxygen at 480 ° C in the presence of a molten salt as in Example 1 described implemented.
• the product gas mixture leaving the reactor consisted of 27.3 g of hydrogen chloride, 5.9 g of oxygen, 52.6 g of chlorine and 13.3 g of water vapor.
• the product gases in an injection cooler cooled to 150 ° C. with aqueous hydrochloric acid, the Water of reaction separated in an absorption tower as aqueous hydrochloric acid, the Product gases with conc. Dried sulfuric acid and chlorine by compression 6 bar and cooling to -10 ° C in liquid form.
• the product gas mixture leaving the reactor consisted of 361.7 g per hour Hydrogen chloride, 75.6 g oxygen, 44.3 g chlorine and 11.25 g water vapor.
• the product gases were in an injection cooler aqueous hydrochloric acid cooled to 150 ° C, the water of reaction in an absorption tower separated as aqueous hydrochloric acid, the product gases with conc. sulfuric acid dried and chlorine by compressing to 6 bar and cooling to -10 ° C in taken in liquid form.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Inorganic Compounds Of Heavy Metals (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6533283

Family Applications (1)

Country Status (8)

Families Citing this family (7)

Family Cites Families (4)

• 1994
  • 1994-11-14 DE DE4440642A patent/DE4440642A1/de not_active Withdrawn
• 1995
  • 1995-11-02 DE DE59506153T patent/DE59506153D1/de not_active Expired - Fee Related
  • 1995-11-02 AT AT95117253T patent/ATE181038T1/de not_active IP Right Cessation
  • 1995-11-02 EP EP95117253A patent/EP0711728B1/de not_active Expired - Lifetime
  • 1995-11-08 JP JP7314664A patent/JPH08225304A/ja active Pending
  • 1995-11-10 CA CA002162641A patent/CA2162641A1/en not_active Abandoned
  • 1995-11-13 KR KR1019950040968A patent/KR960017502A/ko not_active Application Discontinuation
  • 1995-11-13 BR BR9505150A patent/BR9505150A/pt not_active Application Discontinuation
  • 1995-11-14 CN CN95119831A patent/CN1129192A/zh active Pending

Also Published As

Similar Documents

Legal Events